Cancer is a leading cause of premature deaths in the developed world. The aim of immunotherapy in cancer is to mount an effective immune response by the body against a tumour. The key effector cell of a long lasting anti-tumor immune response is the activated tumor specific effector T cell. Cancer patients usually have T-cells specific for tumor antigens, however, the activity of these T-cells is frequently suppressed by inhibitory factors and pathways in the tumor micro-environment. Accordingly, there exists a need for methods for preventing or treating cancer which augment the T cell anti-tumour response.